package 反转链表206;

import java.util.List;

/**
 * @author 谢阳
 * @version 1.8.0_131
 * 给你单链表的头节点 head ，请你反转链表，并返回反转后的链表。
 */


 class ListNode {
    int val;
    ListNode next;

    ListNode() {
    }

    ListNode(int val) {
        this.val = val;
    }

    ListNode(int val, ListNode next) {
        this.val = val;
        this.next = next;
    }
}

class Solution {
    public ListNode reverseList(ListNode head) {
        if (head == null || head.next == null) {
            return head;
        }

        ListNode listNode_reverse = reverseList(head.next);
        head.next.next = head;
        head.next = null;
        return listNode_reverse;
    }
}